The proposed research is a renewal for our investigations of the epidemiology, and genetic-environmental interaction in the etiology of non-insulin dependent diabetes mellitus (NIDDM). The emergence of diabetes in the Pacific islanders has been concomitant with rapid social economic and environmental changes. Socioeconomic change, however, may not be be the only factor contributing to the increased rates of diabetes as there appear to be marked differences in susceptibility to NIDDM between ethnic groups in the region. We intend to utilize the opportunities presented in the Pacific by cross-sectional and longitudinal epidemiology studies, family studies and cross-cultural comparisons in a number of ethnic groups - Polynesians, Micronesians, Melanesians, Indians (migrant Asian) and Caucasoids. The major objectives of the proposed research are: 1. To define the epidemiology and natural history of NIDDM and its complications in these populations. 2. To determine whether foreign genetic admixture influences the prevalence of NIDDM in the various ethnic groups in the Pacific. 3. To determine whether specific genetic markers exist in subject with, or at risk of, NIDDM. 4. To determine whether there are ethnic groups protected from NIDDM and whether such protection is related to the presence of specific genetic markers, or protection from environmental risk factors. 5. To establish the role of environmental risk factors e.g. diet, obesity, physical inactivity etc. in the aetiology of NIDDM in these populations. 6. To define the natural history of IGT in these ethnic groups. The proposed research is of relevance as NIDDM may be potentially preventable. Thus, the elucidation of methods to detect "at risk" individuals, and a greater understanding of environmental precipitating factors could provide important directions for the development of prevention and control programmes.